diff --git a/contrib/btree_gist/btree_text.c b/contrib/btree_gist/btree_text.c
index 8019d11281..985848cd46 100644
--- a/contrib/btree_gist/btree_text.c
+++ b/contrib/btree_gist/btree_text.c
@@ -6,6 +6,7 @@
 #include "btree_gist.h"
 #include "btree_utils_var.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 
 /*
 ** Text ops
diff --git a/contrib/btree_gist/btree_utils_var.c b/contrib/btree_gist/btree_utils_var.c
index 452241f697..9ff97d404c 100644
--- a/contrib/btree_gist/btree_utils_var.c
+++ b/contrib/btree_gist/btree_utils_var.c
@@ -10,6 +10,7 @@
 #include "btree_gist.h"
 #include "btree_utils_var.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 #include "utils/pg_locale.h"
 #include "utils/rel.h"
 
diff --git a/contrib/btree_gist/btree_utils_var.h b/contrib/btree_gist/btree_utils_var.h
index 2f8def655c..4ae273d767 100644
--- a/contrib/btree_gist/btree_utils_var.h
+++ b/contrib/btree_gist/btree_utils_var.h
@@ -6,7 +6,7 @@
 
 #include "access/gist.h"
 #include "btree_gist.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 /* Variable length key */
 typedef bytea GBT_VARKEY;
diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c
index 1dddf02779..e26bdc55c4 100644
--- a/contrib/dblink/dblink.c
+++ b/contrib/dblink/dblink.c
@@ -49,7 +49,7 @@
 #include "funcapi.h"
 #include "lib/stringinfo.h"
 #include "libpq-fe.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "parser/scansup.h"
 #include "utils/acl.h"
@@ -57,6 +57,7 @@
 #include "utils/fmgroids.h"
 #include "utils/guc.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/varlena.h"
diff --git a/contrib/dict_xsyn/dict_xsyn.c b/contrib/dict_xsyn/dict_xsyn.c
index 1065d64ccb..872710096e 100644
--- a/contrib/dict_xsyn/dict_xsyn.c
+++ b/contrib/dict_xsyn/dict_xsyn.c
@@ -17,6 +17,7 @@
 #include "commands/defrem.h"
 #include "tsearch/ts_locale.h"
 #include "tsearch/ts_utils.h"
+#include "utils/mbutils.h"
 
 PG_MODULE_MAGIC;
 
diff --git a/contrib/fuzzystrmatch/fuzzystrmatch.c b/contrib/fuzzystrmatch/fuzzystrmatch.c
index ccbb84b481..aa0a209dab 100644
--- a/contrib/fuzzystrmatch/fuzzystrmatch.c
+++ b/contrib/fuzzystrmatch/fuzzystrmatch.c
@@ -40,7 +40,7 @@
 
 #include <ctype.h>
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "utils/builtins.h"
 #include "utils/varlena.h"
 
diff --git a/contrib/ltree/lquery_op.c b/contrib/ltree/lquery_op.c
index fa47710439..cb486f873a 100644
--- a/contrib/ltree/lquery_op.c
+++ b/contrib/ltree/lquery_op.c
@@ -10,6 +10,7 @@
 #include "catalog/pg_collation.h"
 #include "ltree.h"
 #include "utils/formatting.h"
+#include "utils/mbutils.h"
 
 PG_FUNCTION_INFO_V1(ltq_regex);
 PG_FUNCTION_INFO_V1(ltq_rregex);
diff --git a/contrib/ltree/ltree_io.c b/contrib/ltree/ltree_io.c
index 900a46a9e7..195a948981 100644
--- a/contrib/ltree/ltree_io.c
+++ b/contrib/ltree/ltree_io.c
@@ -9,6 +9,7 @@
 
 #include "crc32.h"
 #include "ltree.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 
 PG_FUNCTION_INFO_V1(ltree_in);
diff --git a/contrib/ltree/ltxtquery_io.c b/contrib/ltree/ltxtquery_io.c
index db347f7772..b7dba1d9fc 100644
--- a/contrib/ltree/ltxtquery_io.c
+++ b/contrib/ltree/ltxtquery_io.c
@@ -7,6 +7,8 @@
 
 #include <ctype.h>
 
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "crc32.h"
 #include "ltree.h"
 #include "miscadmin.h"
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index 6f82a671ee..a2b42a68f5 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -64,7 +64,7 @@
 #include "catalog/pg_authid.h"
 #include "executor/instrument.h"
 #include "funcapi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "parser/analyze.h"
 #include "parser/parsetree.h"
@@ -78,6 +78,7 @@
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/hashutils.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 
 PG_MODULE_MAGIC;
diff --git a/contrib/pg_trgm/trgm_op.c b/contrib/pg_trgm/trgm_op.c
index c9c8cbc734..328b5b4e41 100644
--- a/contrib/pg_trgm/trgm_op.c
+++ b/contrib/pg_trgm/trgm_op.c
@@ -10,6 +10,7 @@
 #include "trgm.h"
 #include "tsearch/ts_locale.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/pg_crc.h"
 
diff --git a/contrib/pg_trgm/trgm_regexp.c b/contrib/pg_trgm/trgm_regexp.c
index 1330b615b8..d148eeee91 100644
--- a/contrib/pg_trgm/trgm_regexp.c
+++ b/contrib/pg_trgm/trgm_regexp.c
@@ -195,6 +195,7 @@
 #include "trgm.h"
 #include "tsearch/ts_locale.h"
 #include "utils/hsearch.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 
 /*
diff --git a/contrib/pgcrypto/pgp-pgsql.c b/contrib/pgcrypto/pgp-pgsql.c
index 8be895df80..7057076f48 100644
--- a/contrib/pgcrypto/pgp-pgsql.c
+++ b/contrib/pgcrypto/pgp-pgsql.c
@@ -34,12 +34,13 @@
 #include "catalog/pg_type.h"
 #include "funcapi.h"
 #include "lib/stringinfo.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "mbuf.h"
 #include "pgp.h"
 #include "px.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 
 /*
  * public functions
diff --git a/contrib/postgres_fdw/connection.c b/contrib/postgres_fdw/connection.c
index 29c811a80b..6c0b13a80c 100644
--- a/contrib/postgres_fdw/connection.c
+++ b/contrib/postgres_fdw/connection.c
@@ -16,13 +16,14 @@
 #include "access/xact.h"
 #include "catalog/pg_user_mapping.h"
 #include "commands/defrem.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "pgstat.h"
 #include "postgres_fdw.h"
 #include "storage/latch.h"
 #include "utils/hsearch.h"
 #include "utils/inval.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/syscache.h"
 
diff --git a/contrib/unaccent/unaccent.c b/contrib/unaccent/unaccent.c
index 0047efc075..04377736b3 100644
--- a/contrib/unaccent/unaccent.c
+++ b/contrib/unaccent/unaccent.c
@@ -22,6 +22,7 @@
 #include "tsearch/ts_public.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/regproc.h"
 #include "utils/syscache.h"
 
diff --git a/src/backend/access/spgist/spgtextproc.c b/src/backend/access/spgist/spgtextproc.c
index b5ec81937c..f56424ef5c 100644
--- a/src/backend/access/spgist/spgtextproc.c
+++ b/src/backend/access/spgist/spgtextproc.c
@@ -41,9 +41,10 @@
 
 #include "access/spgist.h"
 #include "catalog/pg_type.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "utils/builtins.h"
 #include "utils/datum.h"
+#include "utils/mbutils.h"
 #include "utils/pg_locale.h"
 #include "utils/varlena.h"
 
diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index f3e2254954..a551cbba35 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -38,6 +38,7 @@
 #include "utils/combocid.h"
 #include "utils/guc.h"
 #include "utils/inval.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
 #include "utils/snapmgr.h"
diff --git a/src/backend/catalog/genbki.pl b/src/backend/catalog/genbki.pl
index 887fb28578..49d01a3485 100644
--- a/src/backend/catalog/genbki.pl
+++ b/src/backend/catalog/genbki.pl
@@ -308,7 +308,7 @@ foreach my $row (@{ $catalog_data{pg_type} })
 # as for OIDs, but we have to dig the values out of pg_wchar.h.
 my %encids;
 
-my $encfile = $include_path . 'mb/pg_wchar.h';
+my $encfile = $include_path . 'common/pg_wchar.h';
 open(my $ef, '<', $encfile) || die "$encfile: $!";
 
 # We're parsing an enum, so start with 0 and increment
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index e70243a008..ca77289e27 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -41,7 +41,7 @@
 #include "catalog/pg_type.h"
 #include "commands/dbcommands.h"
 #include "funcapi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "parser/parse_func.h"
@@ -54,6 +54,7 @@
 #include "utils/guc.h"
 #include "utils/inval.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/syscache.h"
 #include "utils/varlena.h"
diff --git a/src/backend/catalog/pg_collation.c b/src/backend/catalog/pg_collation.c
index 8559779a4f..2f07f45fdc 100644
--- a/src/backend/catalog/pg_collation.c
+++ b/src/backend/catalog/pg_collation.c
@@ -24,9 +24,10 @@
 #include "catalog/objectaccess.h"
 #include "catalog/pg_collation.h"
 #include "catalog/pg_namespace.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "utils/builtins.h"
 #include "utils/fmgroids.h"
+#include "utils/mbutils.h"
 #include "utils/pg_locale.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
diff --git a/src/backend/catalog/pg_conversion.c b/src/backend/catalog/pg_conversion.c
index b38df4f696..1163aa709a 100644
--- a/src/backend/catalog/pg_conversion.c
+++ b/src/backend/catalog/pg_conversion.c
@@ -25,7 +25,7 @@
 #include "catalog/pg_conversion.h"
 #include "catalog/pg_namespace.h"
 #include "catalog/pg_proc.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "utils/builtins.h"
 #include "utils/catcache.h"
 #include "utils/fmgroids.h"
diff --git a/src/backend/catalog/pg_proc.c b/src/backend/catalog/pg_proc.c
index 5194dcaac0..3f9d036a70 100644
--- a/src/backend/catalog/pg_proc.c
+++ b/src/backend/catalog/pg_proc.c
@@ -29,7 +29,7 @@
 #include "commands/defrem.h"
 #include "executor/functions.h"
 #include "funcapi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
 #include "parser/parse_type.h"
@@ -38,6 +38,7 @@
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/regproc.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
diff --git a/src/backend/commands/collationcmds.c b/src/backend/commands/collationcmds.c
index 34c75e8b56..2869cb68a4 100644
--- a/src/backend/commands/collationcmds.c
+++ b/src/backend/commands/collationcmds.c
@@ -27,10 +27,11 @@
 #include "commands/comment.h"
 #include "commands/dbcommands.h"
 #include "commands/defrem.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/pg_locale.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
diff --git a/src/backend/commands/conversioncmds.c b/src/backend/commands/conversioncmds.c
index f974478b26..87b4cc1090 100644
--- a/src/backend/commands/conversioncmds.c
+++ b/src/backend/commands/conversioncmds.c
@@ -21,7 +21,7 @@
 #include "catalog/pg_type.h"
 #include "commands/alter.h"
 #include "commands/conversioncmds.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "parser/parse_func.h"
 #include "utils/builtins.h"
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 40a8ec1abd..cd86236955 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -37,7 +37,7 @@
 #include "foreign/fdwapi.h"
 #include "libpq/libpq.h"
 #include "libpq/pqformat.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "optimizer/optimizer.h"
@@ -51,6 +51,7 @@
 #include "tcop/tcopprot.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/partcache.h"
 #include "utils/portal.h"
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 367c30adb0..0a6e6c6c6b 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -46,7 +46,7 @@
 #include "commands/defrem.h"
 #include "commands/seclabel.h"
 #include "commands/tablespace.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "pgstat.h"
 #include "postmaster/bgwriter.h"
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 01de398dcb..bdba95b0cc 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -51,7 +51,7 @@
 #include "commands/extension.h"
 #include "commands/schemacmds.h"
 #include "funcapi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "storage/fd.h"
@@ -60,6 +60,7 @@
 #include "utils/builtins.h"
 #include "utils/fmgroids.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/snapmgr.h"
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 52ce02f898..365d610e39 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -39,7 +39,7 @@
 #include "commands/progress.h"
 #include "commands/tablecmds.h"
 #include "commands/tablespace.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
@@ -59,6 +59,7 @@
 #include "utils/fmgroids.h"
 #include "utils/inval.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/partcache.h"
 #include "utils/pg_rusage.h"
diff --git a/src/backend/commands/variable.c b/src/backend/commands/variable.c
index 484f7ea2c0..e27957bc5b 100644
--- a/src/backend/commands/variable.c
+++ b/src/backend/commands/variable.c
@@ -24,10 +24,11 @@
 #include "access/xlog.h"
 #include "catalog/pg_authid.h"
 #include "commands/variable.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 #include "utils/snapmgr.h"
 #include "utils/syscache.h"
 #include "utils/timestamp.h"
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index b03e02ae6c..f3237067af 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -51,7 +51,7 @@
 #include "executor/nodeSubplan.h"
 #include "foreign/fdwapi.h"
 #include "jit/jit.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "parser/parsetree.h"
 #include "storage/bufmgr.h"
@@ -59,6 +59,7 @@
 #include "tcop/utility.h"
 #include "utils/acl.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/partcache.h"
 #include "utils/rls.h"
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
index c13b1d3501..986c545af3 100644
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -21,7 +21,7 @@
 #include "executor/execPartition.h"
 #include "executor/executor.h"
 #include "foreign/fdwapi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "partitioning/partbounds.h"
@@ -29,6 +29,7 @@
 #include "partitioning/partprune.h"
 #include "rewrite/rewriteManip.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/partcache.h"
 #include "utils/rls.h"
 #include "utils/ruleutils.h"
diff --git a/src/backend/executor/execUtils.c b/src/backend/executor/execUtils.c
index cc5177cc2b..751d6aca14 100644
--- a/src/backend/executor/execUtils.c
+++ b/src/backend/executor/execUtils.c
@@ -52,12 +52,13 @@
 #include "access/transam.h"
 #include "executor/executor.h"
 #include "jit/jit.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "nodes/nodeFuncs.h"
 #include "parser/parsetree.h"
 #include "partitioning/partdesc.h"
 #include "storage/lmgr.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/typcache.h"
diff --git a/src/backend/libpq/hba.c b/src/backend/libpq/hba.c
index d2a63e9e56..93794d0096 100644
--- a/src/backend/libpq/hba.c
+++ b/src/backend/libpq/hba.c
@@ -43,6 +43,7 @@
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
 #include "utils/varlena.h"
+#include "utils/mbutils.h"
 
 #ifdef USE_LDAP
 #ifdef WIN32
diff --git a/src/backend/libpq/pqformat.c b/src/backend/libpq/pqformat.c
index a6f990c2d2..f52e2ff5c0 100644
--- a/src/backend/libpq/pqformat.c
+++ b/src/backend/libpq/pqformat.c
@@ -75,7 +75,7 @@
 
 #include "libpq/libpq.h"
 #include "libpq/pqformat.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "port/pg_bswap.h"
 
 
diff --git a/src/backend/parser/parse_node.c b/src/backend/parser/parse_node.c
index 6e98fe55fc..c5993d01c5 100644
--- a/src/backend/parser/parse_node.c
+++ b/src/backend/parser/parse_node.c
@@ -17,7 +17,7 @@
 #include "access/htup_details.h"
 #include "access/table.h"
 #include "catalog/pg_type.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "parser/parse_coerce.h"
@@ -27,6 +27,7 @@
 #include "utils/builtins.h"
 #include "utils/int8.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/syscache.h"
 #include "utils/varbit.h"
 
diff --git a/src/backend/parser/parser.c b/src/backend/parser/parser.c
index 1bf1144c4f..6d27d1c5b7 100644
--- a/src/backend/parser/parser.c
+++ b/src/backend/parser/parser.c
@@ -21,10 +21,11 @@
 
 #include "postgres.h"
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "parser/gramparse.h"
 #include "parser/parser.h"
 #include "parser/scansup.h"
+#include "utils/mbutils.h"
 
 static bool check_uescapechar(unsigned char escape);
 static char *str_udeescape(const char *str, char escape,
diff --git a/src/backend/parser/scan.l b/src/backend/parser/scan.l
index 84c73914a8..05b6f17bbd 100644
--- a/src/backend/parser/scan.l
+++ b/src/backend/parser/scan.l
@@ -39,7 +39,8 @@
 #include "parser/gramparse.h"
 #include "parser/parser.h"		/* only needed for GUC variables */
 #include "parser/scansup.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 }
 
 %{
diff --git a/src/backend/parser/scansup.c b/src/backend/parser/scansup.c
index 18169ec4f4..6fc2b59fa3 100644
--- a/src/backend/parser/scansup.c
+++ b/src/backend/parser/scansup.c
@@ -17,8 +17,9 @@
 
 #include <ctype.h>
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "parser/scansup.h"
+#include "utils/mbutils.h"
 
 /* ----------------
  *		scanstr
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 51c486bebd..751f017c7d 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -43,7 +43,7 @@
 #include "common/ip.h"
 #include "libpq/libpq.h"
 #include "libpq/pqsignal.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "pg_trace.h"
 #include "pgstat.h"
@@ -63,6 +63,7 @@
 #include "storage/sinvaladt.h"
 #include "utils/ascii.h"
 #include "utils/guc.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/ps_status.h"
 #include "utils/rel.h"
diff --git a/src/backend/regex/regc_pg_locale.c b/src/backend/regex/regc_pg_locale.c
index 3cc2d4d362..5db0d1b749 100644
--- a/src/backend/regex/regc_pg_locale.c
+++ b/src/backend/regex/regc_pg_locale.c
@@ -16,6 +16,7 @@
  */
 
 #include "catalog/pg_collation.h"
+#include "utils/mbutils.h"
 #include "utils/pg_locale.h"
 
 /*
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index e4fd1f9bb6..cff8d5b17d 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -23,12 +23,13 @@
 #include "catalog/pg_type.h"
 #include "funcapi.h"
 #include "libpq-fe.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "pgstat.h"
 #include "pqexpbuffer.h"
 #include "replication/walreceiver.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/pg_lsn.h"
 #include "utils/tuplestore.h"
diff --git a/src/backend/replication/logical/logicalfuncs.c b/src/backend/replication/logical/logicalfuncs.c
index 7693c98949..a286c4ab82 100644
--- a/src/backend/replication/logical/logicalfuncs.c
+++ b/src/backend/replication/logical/logicalfuncs.c
@@ -23,7 +23,7 @@
 #include "catalog/pg_type.h"
 #include "fmgr.h"
 #include "funcapi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "replication/decode.h"
@@ -35,6 +35,7 @@
 #include "utils/builtins.h"
 #include "utils/inval.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/pg_lsn.h"
 #include "utils/regproc.h"
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index 7a5471f95c..c661ac4acf 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -38,7 +38,7 @@
 #include "funcapi.h"
 #include "libpq/pqformat.h"
 #include "libpq/pqsignal.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "optimizer/optimizer.h"
diff --git a/src/backend/snowball/dict_snowball.c b/src/backend/snowball/dict_snowball.c
index 144120a564..03a41c80ec 100644
--- a/src/backend/snowball/dict_snowball.c
+++ b/src/backend/snowball/dict_snowball.c
@@ -15,6 +15,7 @@
 #include "commands/defrem.h"
 #include "tsearch/ts_locale.h"
 #include "tsearch/ts_utils.h"
+#include "utils/mbutils.h"
 
 /* Some platforms define MAXINT and/or MININT, causing conflicts */
 #ifdef MAXINT
diff --git a/src/backend/tcop/fastpath.c b/src/backend/tcop/fastpath.c
index e793984a9f..7ba382aa3a 100644
--- a/src/backend/tcop/fastpath.c
+++ b/src/backend/tcop/fastpath.c
@@ -23,7 +23,7 @@
 #include "catalog/pg_proc.h"
 #include "libpq/libpq.h"
 #include "libpq/pqformat.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "port/pg_bswap.h"
 #include "tcop/fastpath.h"
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 0a6f80963b..a5d1e199a0 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -47,7 +47,7 @@
 #include "libpq/libpq.h"
 #include "libpq/pqformat.h"
 #include "libpq/pqsignal.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "mb/stringinfo_mb.h"
 #include "miscadmin.h"
 #include "nodes/print.h"
diff --git a/src/backend/tsearch/dict_synonym.c b/src/backend/tsearch/dict_synonym.c
index e732e66dac..343e82b1bf 100644
--- a/src/backend/tsearch/dict_synonym.c
+++ b/src/backend/tsearch/dict_synonym.c
@@ -17,6 +17,7 @@
 #include "tsearch/ts_locale.h"
 #include "tsearch/ts_utils.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 
 typedef struct
 {
diff --git a/src/backend/tsearch/dict_thesaurus.c b/src/backend/tsearch/dict_thesaurus.c
index fb91a34b02..a6b6e0880c 100644
--- a/src/backend/tsearch/dict_thesaurus.c
+++ b/src/backend/tsearch/dict_thesaurus.c
@@ -19,6 +19,7 @@
 #include "tsearch/ts_locale.h"
 #include "tsearch/ts_utils.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 #include "utils/regproc.h"
 
 
diff --git a/src/backend/tsearch/regis.c b/src/backend/tsearch/regis.c
index 2edd4faa8e..46b8434a29 100644
--- a/src/backend/tsearch/regis.c
+++ b/src/backend/tsearch/regis.c
@@ -16,6 +16,7 @@
 
 #include "tsearch/dicts/regis.h"
 #include "tsearch/ts_locale.h"
+#include "utils/mbutils.h"
 
 #define RS_IN_ONEOF 1
 #define RS_IN_ONEOF_IN	2
diff --git a/src/backend/tsearch/spell.c b/src/backend/tsearch/spell.c
index 8aab96d3b0..150f7a9c0f 100644
--- a/src/backend/tsearch/spell.c
+++ b/src/backend/tsearch/spell.c
@@ -66,6 +66,7 @@
 #include "tsearch/dicts/spell.h"
 #include "tsearch/ts_locale.h"
 #include "utils/memutils.h"
+#include "utils/mbutils.h"
 
 
 /*
diff --git a/src/backend/tsearch/ts_locale.c b/src/backend/tsearch/ts_locale.c
index a916dd6cb6..165b194246 100644
--- a/src/backend/tsearch/ts_locale.c
+++ b/src/backend/tsearch/ts_locale.c
@@ -17,6 +17,7 @@
 #include "storage/fd.h"
 #include "tsearch/ts_locale.h"
 #include "tsearch/ts_public.h"
+#include "utils/mbutils.h"
 
 static void tsearch_readline_callback(void *arg);
 
diff --git a/src/backend/tsearch/ts_utils.c b/src/backend/tsearch/ts_utils.c
index 3bc6b32095..280ba72eab 100644
--- a/src/backend/tsearch/ts_utils.c
+++ b/src/backend/tsearch/ts_utils.c
@@ -19,6 +19,7 @@
 #include "miscadmin.h"
 #include "tsearch/ts_locale.h"
 #include "tsearch/ts_utils.h"
+#include "utils/mbutils.h"
 
 
 /*
diff --git a/src/backend/tsearch/wparser_def.c b/src/backend/tsearch/wparser_def.c
index 898466fcef..4fbb985c38 100644
--- a/src/backend/tsearch/wparser_def.c
+++ b/src/backend/tsearch/wparser_def.c
@@ -23,6 +23,7 @@
 #include "tsearch/ts_type.h"
 #include "tsearch/ts_utils.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 
 
 /* Define me to enable tracing of parser behavior */
diff --git a/src/backend/utils/adt/ascii.c b/src/backend/utils/adt/ascii.c
index 3aa8a5e7d2..b692aed409 100644
--- a/src/backend/utils/adt/ascii.c
+++ b/src/backend/utils/adt/ascii.c
@@ -11,9 +11,10 @@
  */
 #include "postgres.h"
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "utils/ascii.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 
 static void pg_to_ascii(unsigned char *src, unsigned char *src_end,
 						unsigned char *dest, int enc);
diff --git a/src/backend/utils/adt/format_type.c b/src/backend/utils/adt/format_type.c
index 92ee77ac5c..1e8f1a2189 100644
--- a/src/backend/utils/adt/format_type.c
+++ b/src/backend/utils/adt/format_type.c
@@ -20,9 +20,10 @@
 #include "access/htup_details.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_type.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/numeric.h"
 #include "utils/syscache.h"
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index ca3c48d024..cadee997a1 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -87,13 +87,14 @@
 
 #include "catalog/pg_collation.h"
 #include "catalog/pg_type.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "utils/builtins.h"
 #include "utils/date.h"
 #include "utils/datetime.h"
 #include "utils/float.h"
 #include "utils/formatting.h"
 #include "utils/int8.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/numeric.h"
 #include "utils/pg_locale.h"
diff --git a/src/backend/utils/adt/genfile.c b/src/backend/utils/adt/genfile.c
index 0d75928e7f..6bfca411b7 100644
--- a/src/backend/utils/adt/genfile.c
+++ b/src/backend/utils/adt/genfile.c
@@ -26,11 +26,12 @@
 #include "catalog/pg_tablespace_d.h"
 #include "catalog/pg_type.h"
 #include "funcapi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "postmaster/syslogger.h"
 #include "storage/fd.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/syscache.h"
 #include "utils/timestamp.h"
diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c
index 458505abfd..c0a7afb9a6 100644
--- a/src/backend/utils/adt/json.c
+++ b/src/backend/utils/adt/json.c
@@ -20,7 +20,7 @@
 #include "funcapi.h"
 #include "lib/stringinfo.h"
 #include "libpq/pqformat.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "parser/parse_coerce.h"
 #include "utils/array.h"
@@ -30,6 +30,7 @@
 #include "utils/json.h"
 #include "utils/jsonapi.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/syscache.h"
 #include "utils/typcache.h"
 
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 4b5a0214dc..ee75fc34c4 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,7 +21,7 @@
 #include "fmgr.h"
 #include "funcapi.h"
 #include "lib/stringinfo.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
diff --git a/src/backend/utils/adt/jsonpath_exec.c b/src/backend/utils/adt/jsonpath_exec.c
index 6b9bd00bb7..abdc0149b2 100644
--- a/src/backend/utils/adt/jsonpath_exec.c
+++ b/src/backend/utils/adt/jsonpath_exec.c
@@ -74,6 +74,7 @@
 #include "utils/guc.h"
 #include "utils/json.h"
 #include "utils/jsonpath.h"
+#include "utils/mbutils.h"
 #include "utils/timestamp.h"
 #include "utils/varlena.h"
 
diff --git a/src/backend/utils/adt/jsonpath_scan.l b/src/backend/utils/adt/jsonpath_scan.l
index 70681b789d..d522b18097 100644
--- a/src/backend/utils/adt/jsonpath_scan.l
+++ b/src/backend/utils/adt/jsonpath_scan.l
@@ -17,8 +17,9 @@
 
 #include "postgres.h"
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "nodes/pg_list.h"
+#include "utils/mbutils.h"
 
 static JsonPathString scanstring;
 
diff --git a/src/backend/utils/adt/like.c b/src/backend/utils/adt/like.c
index 5bf94628c3..ef80cdbf15 100644
--- a/src/backend/utils/adt/like.c
+++ b/src/backend/utils/adt/like.c
@@ -20,9 +20,10 @@
 #include <ctype.h>
 
 #include "catalog/pg_collation.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 #include "utils/pg_locale.h"
 
 
diff --git a/src/backend/utils/adt/like_match.c b/src/backend/utils/adt/like_match.c
index ee30170fbb..b05255761c 100644
--- a/src/backend/utils/adt/like_match.c
+++ b/src/backend/utils/adt/like_match.c
@@ -57,6 +57,7 @@
  * - thomas 2000-08-06
  */
 
+#include "utils/mbutils.h"
 
 /*--------------------
  *	Match text and pattern, return LIKE_TRUE, LIKE_FALSE, or LIKE_ABORT.
diff --git a/src/backend/utils/adt/like_support.c b/src/backend/utils/adt/like_support.c
index 286e000d4e..837b7dc153 100644
--- a/src/backend/utils/adt/like_support.c
+++ b/src/backend/utils/adt/like_support.c
@@ -43,13 +43,14 @@
 #include "catalog/pg_opfamily.h"
 #include "catalog/pg_statistic.h"
 #include "catalog/pg_type.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "nodes/supportnodes.h"
 #include "utils/builtins.h"
 #include "utils/datum.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/pg_locale.h"
 #include "utils/selfuncs.h"
 #include "utils/varlena.h"
diff --git a/src/backend/utils/adt/name.c b/src/backend/utils/adt/name.c
index 6749e75c89..89d485889a 100644
--- a/src/backend/utils/adt/name.c
+++ b/src/backend/utils/adt/name.c
@@ -24,11 +24,12 @@
 #include "catalog/pg_collation.h"
 #include "catalog/pg_type.h"
 #include "libpq/pqformat.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/varlena.h"
 
 
diff --git a/src/backend/utils/adt/oracle_compat.c b/src/backend/utils/adt/oracle_compat.c
index 0d56dc898a..7ff845e735 100644
--- a/src/backend/utils/adt/oracle_compat.c
+++ b/src/backend/utils/adt/oracle_compat.c
@@ -16,9 +16,10 @@
 #include "postgres.h"
 
 #include "common/int.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "utils/builtins.h"
 #include "utils/formatting.h"
+#include "utils/mbutils.h"
 
 static text *dotrim(const char *string, int stringlen,
 					const char *set, int setlen,
diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index 25fb7e2ebf..c7174e33ad 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -57,11 +57,12 @@
 #include "access/htup_details.h"
 #include "catalog/pg_collation.h"
 #include "catalog/pg_control.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "utils/builtins.h"
 #include "utils/formatting.h"
 #include "utils/hsearch.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/pg_locale.h"
 #include "utils/syscache.h"
diff --git a/src/backend/utils/adt/regexp.c b/src/backend/utils/adt/regexp.c
index 6c76e89c9a..ca29918441 100644
--- a/src/backend/utils/adt/regexp.c
+++ b/src/backend/utils/adt/regexp.c
@@ -35,6 +35,7 @@
 #include "regex/regex.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/varlena.h"
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 116e00bce4..bd563da92a 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -45,7 +45,7 @@
 #include "common/keywords.h"
 #include "executor/spi.h"
 #include "funcapi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
@@ -66,6 +66,7 @@
 #include "utils/guc.h"
 #include "utils/hsearch.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/partcache.h"
 #include "utils/rel.h"
 #include "utils/ruleutils.h"
diff --git a/src/backend/utils/adt/tsquery.c b/src/backend/utils/adt/tsquery.c
index 092e8a130b..c4635e0ee3 100644
--- a/src/backend/utils/adt/tsquery.c
+++ b/src/backend/utils/adt/tsquery.c
@@ -20,6 +20,7 @@
 #include "tsearch/ts_type.h"
 #include "tsearch/ts_utils.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/pg_crc.h"
 
diff --git a/src/backend/utils/adt/tsvector.c b/src/backend/utils/adt/tsvector.c
index cd3bb9b63e..7106457431 100644
--- a/src/backend/utils/adt/tsvector.c
+++ b/src/backend/utils/adt/tsvector.c
@@ -18,6 +18,7 @@
 #include "tsearch/ts_locale.h"
 #include "tsearch/ts_utils.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 
 typedef struct
diff --git a/src/backend/utils/adt/tsvector_op.c b/src/backend/utils/adt/tsvector_op.c
index e33ca5abe7..fbbf3bdbae 100644
--- a/src/backend/utils/adt/tsvector_op.c
+++ b/src/backend/utils/adt/tsvector_op.c
@@ -22,13 +22,14 @@
 #include "executor/spi.h"
 #include "funcapi.h"
 #include "lib/qunique.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "parser/parse_coerce.h"
 #include "tsearch/ts_utils.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/regproc.h"
 #include "utils/rel.h"
 
diff --git a/src/backend/utils/adt/tsvector_parser.c b/src/backend/utils/adt/tsvector_parser.c
index cfc181c20d..11defd95cd 100644
--- a/src/backend/utils/adt/tsvector_parser.c
+++ b/src/backend/utils/adt/tsvector_parser.c
@@ -16,6 +16,7 @@
 
 #include "tsearch/ts_locale.h"
 #include "tsearch/ts_utils.h"
+#include "utils/mbutils.h"
 
 
 /*
diff --git a/src/backend/utils/adt/varchar.c b/src/backend/utils/adt/varchar.c
index 1e1239a1ba..fb80a08f36 100644
--- a/src/backend/utils/adt/varchar.c
+++ b/src/backend/utils/adt/varchar.c
@@ -18,13 +18,14 @@
 #include "catalog/pg_collation.h"
 #include "catalog/pg_type.h"
 #include "libpq/pqformat.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "nodes/nodeFuncs.h"
 #include "nodes/supportnodes.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hashutils.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/pg_locale.h"
 #include "utils/varlena.h"
 
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index 1b351cbc68..e2029ade81 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -31,6 +31,7 @@
 #include "utils/bytea.h"
 #include "utils/hashutils.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/pg_locale.h"
 #include "utils/sortsupport.h"
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 3808c307f6..855843a843 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -78,7 +78,7 @@
 #include "fmgr.h"
 #include "lib/stringinfo.h"
 #include "libpq/pqformat.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/execnodes.h"
 #include "nodes/nodeFuncs.h"
@@ -87,6 +87,7 @@
 #include "utils/date.h"
 #include "utils/datetime.h"
 #include "utils/lsyscache.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/rel.h"
 #include "utils/syscache.h"
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index f5b0211f66..5db5520504 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -70,7 +70,7 @@
 #include "access/xact.h"
 #include "libpq/libpq.h"
 #include "libpq/pqformat.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "postmaster/postmaster.h"
 #include "postmaster/syslogger.h"
@@ -78,6 +78,7 @@
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
 #include "utils/guc.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/ps_status.h"
 
diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c
index c4b2946986..503175fbf3 100644
--- a/src/backend/utils/init/miscinit.c
+++ b/src/backend/utils/init/miscinit.c
@@ -34,7 +34,7 @@
 #include "catalog/pg_authid.h"
 #include "common/file_perm.h"
 #include "libpq/libpq.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "pgstat.h"
 #include "postmaster/autovacuum.h"
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 8a47dcdcb1..98195f1ea5 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -36,7 +36,7 @@
 #include "catalog/pg_tablespace.h"
 #include "libpq/auth.h"
 #include "libpq/libpq-be.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "pgstat.h"
 #include "postmaster/autovacuum.h"
@@ -56,6 +56,7 @@
 #include "utils/acl.h"
 #include "utils/fmgroids.h"
 #include "utils/guc.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/pg_locale.h"
 #include "utils/portal.h"
diff --git a/src/backend/utils/mb/conv.c b/src/backend/utils/mb/conv.c
index 54dcf71fb7..3b68dd4821 100644
--- a/src/backend/utils/mb/conv.c
+++ b/src/backend/utils/mb/conv.c
@@ -11,7 +11,8 @@
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 
 
 /*
diff --git a/src/backend/utils/mb/conversion_procs/README.euc_jp b/src/backend/utils/mb/conversion_procs/README.euc_jp
index 6e59b7bd7f..97cc63f1bd 100644
--- a/src/backend/utils/mb/conversion_procs/README.euc_jp
+++ b/src/backend/utils/mb/conversion_procs/README.euc_jp
@@ -35,7 +35,7 @@ o C
   ソース文字列の長さ(5番目の引数で指定されます．単位はNULLターミネート
   を含まないバイト数です)とは一致しないからです．
 
-  エンコーディングIDはinclude/mb/pg_wchar.hのtypedef enum pg_encで定義
+  エンコーディングIDはinclude/common/pg_wchar.hのtypedef enum pg_encで定義
   されています．
 
 o 関数の登録とコンパイル
diff --git a/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c b/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c
index 376b48ca61..0c951c6901 100644
--- a/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/cyrillic_and_mic/cyrillic_and_mic.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 
 PG_MODULE_MAGIC;
 
diff --git a/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c b/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c
index 9ba6bd3040..26d0f21140 100644
--- a/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c
+++ b/src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c
@@ -12,7 +12,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 
 PG_MODULE_MAGIC;
 
diff --git a/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c b/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c
index 59c6c3bb12..c3c324c9f5 100644
--- a/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/euc_cn_and_mic/euc_cn_and_mic.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 
 PG_MODULE_MAGIC;
 
diff --git a/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c b/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c
index 4ca8e2126e..b24148c90b 100644
--- a/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c
+++ b/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 
 /*
  * SJIS alternative code.
diff --git a/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c b/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c
index 4d7876a666..273fce16f7 100644
--- a/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 
 PG_MODULE_MAGIC;
 
diff --git a/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/big5.c b/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/big5.c
index 68f76aa8cb..7601bd65f2 100644
--- a/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/big5.c
+++ b/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/big5.c
@@ -13,7 +13,7 @@
 /* can be used in either frontend or backend */
 #include "postgres_fe.h"
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 typedef struct
 {
diff --git a/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c b/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c
index 82a22b9beb..fe40e2429f 100644
--- a/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c
+++ b/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 
 #define ENCODING_GROWTH_RATE 4
 
diff --git a/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c b/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c
index f424f88145..21a82ffd88 100644
--- a/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c
+++ b/src/backend/utils/mb/conversion_procs/latin2_and_win1250/latin2_and_win1250.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 
 PG_MODULE_MAGIC;
 
diff --git a/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c b/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c
index a358a707c1..bb40d91922 100644
--- a/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c
+++ b/src/backend/utils/mb/conversion_procs/latin_and_mic/latin_and_mic.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 
 PG_MODULE_MAGIC;
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c b/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c
index 75ed49ac54..f12d96e263 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_big5/utf8_and_big5.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/big5_to_utf8.map"
 #include "../../Unicode/utf8_to_big5.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c b/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c
index 90ad316111..49317d6417 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/utf8_to_koi8r.map"
 #include "../../Unicode/koi8r_to_utf8.map"
 #include "../../Unicode/utf8_to_koi8u.map"
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c
index 018312489c..808ccf3b1d 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc2004/utf8_and_euc2004.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/euc_jis_2004_to_utf8.map"
 #include "../../Unicode/utf8_to_euc_jis_2004.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c
index 62182a9ba8..c4eb2eb879 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_cn/utf8_and_euc_cn.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/euc_cn_to_utf8.map"
 #include "../../Unicode/utf8_to_euc_cn.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c
index dc5abb5dfd..717106b2a1 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_jp/utf8_and_euc_jp.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/euc_jp_to_utf8.map"
 #include "../../Unicode/utf8_to_euc_jp.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c
index 088a38d839..1885b1d1ef 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_kr/utf8_and_euc_kr.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/euc_kr_to_utf8.map"
 #include "../../Unicode/utf8_to_euc_kr.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c b/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c
index a9fe94f88b..3f1b8b36cc 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_euc_tw/utf8_and_euc_tw.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/euc_tw_to_utf8.map"
 #include "../../Unicode/utf8_to_euc_tw.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c b/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c
index 96909b5885..8a5ac5db27 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_gb18030/utf8_and_gb18030.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/gb18030_to_utf8.map"
 #include "../../Unicode/utf8_to_gb18030.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c b/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c
index 78bbcd3ce7..bb61be10ad 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_gbk/utf8_and_gbk.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/gbk_to_utf8.map"
 #include "../../Unicode/utf8_to_gbk.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c
index 348524f4a2..706b072993 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859/utf8_and_iso8859.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/iso8859_10_to_utf8.map"
 #include "../../Unicode/iso8859_13_to_utf8.map"
 #include "../../Unicode/iso8859_14_to_utf8.map"
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
index 2cdca9f780..2e7a64fa4a 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 
 PG_MODULE_MAGIC;
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c b/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c
index e09a7c8e41..29534f81a4 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_johab/utf8_and_johab.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/johab_to_utf8.map"
 #include "../../Unicode/utf8_to_johab.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c b/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c
index c56fa80a4b..a6f526d3cb 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_sjis/utf8_and_sjis.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/sjis_to_utf8.map"
 #include "../../Unicode/utf8_to_sjis.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c b/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c
index 458500998d..a21f7a72c8 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_sjis2004/utf8_and_sjis2004.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/shift_jis_2004_to_utf8.map"
 #include "../../Unicode/utf8_to_shift_jis_2004.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c b/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c
index 3226ed0325..0ad012282f 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_uhc/utf8_and_uhc.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/uhc_to_utf8.map"
 #include "../../Unicode/utf8_to_uhc.map"
 
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c b/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c
index 1a0074d063..b348f29646 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_win/utf8_and_win.c
@@ -13,7 +13,8 @@
 
 #include "postgres.h"
 #include "fmgr.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 #include "../../Unicode/utf8_to_win1250.map"
 #include "../../Unicode/utf8_to_win1251.map"
 #include "../../Unicode/utf8_to_win1252.map"
diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c
index 86787bcb31..bd3c5b9442 100644
--- a/src/backend/utils/mb/mbutils.c
+++ b/src/backend/utils/mb/mbutils.c
@@ -36,8 +36,9 @@
 
 #include "access/xact.h"
 #include "catalog/namespace.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "utils/builtins.h"
+#include "utils/mbutils.h"
 #include "utils/memutils.h"
 #include "utils/syscache.h"
 
diff --git a/src/backend/utils/mb/stringinfo_mb.c b/src/backend/utils/mb/stringinfo_mb.c
index c153b77007..ce8c181474 100644
--- a/src/backend/utils/mb/stringinfo_mb.c
+++ b/src/backend/utils/mb/stringinfo_mb.c
@@ -20,7 +20,8 @@
 #include "postgres.h"
 
 #include "mb/stringinfo_mb.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
+#include "utils/mbutils.h"
 
 
 /*
diff --git a/src/backend/utils/mb/wstrcmp.c b/src/backend/utils/mb/wstrcmp.c
index dad3ae023a..e5f57d717d 100644
--- a/src/backend/utils/mb/wstrcmp.c
+++ b/src/backend/utils/mb/wstrcmp.c
@@ -35,7 +35,7 @@
 /* can be used in either frontend or backend */
 #include "postgres_fe.h"
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 int
 pg_char_and_wchar_strcmp(const char *s1, const pg_wchar *s2)
diff --git a/src/backend/utils/mb/wstrncmp.c b/src/backend/utils/mb/wstrncmp.c
index ea4823fc6f..cce0c6c5cf 100644
--- a/src/backend/utils/mb/wstrncmp.c
+++ b/src/backend/utils/mb/wstrncmp.c
@@ -34,7 +34,7 @@
 /* can be used in either frontend or backend */
 #include "postgres_fe.h"
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 int
 pg_wchar_strncmp(const pg_wchar *s1, const pg_wchar *s2, size_t n)
diff --git a/src/backend/utils/misc/guc-file.l b/src/backend/utils/misc/guc-file.l
index 268b745528..0738360aa7 100644
--- a/src/backend/utils/misc/guc-file.l
+++ b/src/backend/utils/misc/guc-file.l
@@ -14,10 +14,11 @@
 #include <ctype.h>
 #include <unistd.h>
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "storage/fd.h"
 #include "utils/guc.h"
+#include "utils/mbutils.h"
 
 
 /*
diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c
index 9e24fec72d..b47439c52c 100644
--- a/src/backend/utils/mmgr/mcxt.c
+++ b/src/backend/utils/mmgr/mcxt.c
@@ -21,8 +21,9 @@
 
 #include "postgres.h"
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
+#include "utils/mbutils.h"
 #include "utils/memdebug.h"
 #include "utils/memutils.h"
 
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index ec6d0bdf8e..d3b598e0a5 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -71,7 +71,7 @@
 #include "fe_utils/string_utils.h"
 #include "getaddrinfo.h"
 #include "getopt_long.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 
 
diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index 5f9a102a74..355723b161 100644
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -11,7 +11,7 @@
 
 #include "catalog/pg_authid_d.h"
 #include "fe_utils/string_utils.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "pg_upgrade.h"
 
 static void check_new_cluster_is_empty(void);
diff --git a/src/bin/psql/mainloop.c b/src/bin/psql/mainloop.c
index bdf803a053..bf05cc688d 100644
--- a/src/bin/psql/mainloop.c
+++ b/src/bin/psql/mainloop.c
@@ -12,7 +12,7 @@
 #include "common/logging.h"
 #include "input.h"
 #include "mainloop.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "prompt.h"
 #include "settings.h"
 
diff --git a/src/common/encnames.c b/src/common/encnames.c
index 14cf1b39e9..f06221e1d5 100644
--- a/src/common/encnames.c
+++ b/src/common/encnames.c
@@ -15,7 +15,7 @@
 #include <ctype.h>
 #include <unistd.h>
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 
 /* ----------
@@ -297,7 +297,7 @@ static const pg_encname pg_encname_tbl[] =
 
 /* ----------
  * These are "official" encoding names.
- * XXX must be sorted by the same order as enum pg_enc (in mb/pg_wchar.h)
+ * XXX must be sorted by the same order as enum pg_enc (in common/pg_wchar.h)
  * ----------
  */
 #ifndef WIN32
diff --git a/src/common/saslprep.c b/src/common/saslprep.c
index 7739b81807..a8b2c42949 100644
--- a/src/common/saslprep.c
+++ b/src/common/saslprep.c
@@ -27,7 +27,7 @@
 
 #include "common/saslprep.h"
 #include "common/unicode_norm.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 /*
  * Limit on how large password's we will try to process.  A password
diff --git a/src/common/wchar.c b/src/common/wchar.c
index efaf1c155b..53006115d2 100644
--- a/src/common/wchar.c
+++ b/src/common/wchar.c
@@ -12,7 +12,7 @@
  */
 #include "c.h"
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 
 /*
@@ -1499,7 +1499,7 @@ pg_utf8_islegal(const unsigned char *source, int length)
 /*
  *-------------------------------------------------------------------
  * encoding info table
- * XXX must be sorted by the same order as enum pg_enc (in mb/pg_wchar.h)
+ * XXX must be sorted by the same order as enum pg_enc (in common/pg_wchar.h)
  *-------------------------------------------------------------------
  */
 const pg_wchar_tbl pg_wchar_table[] = {
diff --git a/src/include/catalog/pg_conversion.dat b/src/include/catalog/pg_conversion.dat
index d7120f2fb0..9913d2e370 100644
--- a/src/include/catalog/pg_conversion.dat
+++ b/src/include/catalog/pg_conversion.dat
@@ -11,7 +11,7 @@
 #----------------------------------------------------------------------
 
 # Note: conforencoding and contoencoding must match the spelling of
-# the labels used in the enum pg_enc in mb/pg_wchar.h.
+# the labels used in the enum pg_enc in common/pg_wchar.h.
 
 [
 
diff --git a/src/include/mb/pg_wchar.h b/src/include/common/pg_wchar.h
similarity index 85%
rename from src/include/mb/pg_wchar.h
rename to src/include/common/pg_wchar.h
index b8892ef730..e23cd11df6 100644
--- a/src/include/mb/pg_wchar.h
+++ b/src/include/common/pg_wchar.h
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * src/include/mb/pg_wchar.h
+ * src/include/common/pg_wchar.h
  *
  *	NOTES
  *		This is used both by the backend and by frontends, but should not be
@@ -552,104 +552,25 @@ extern bool pg_utf8_islegal(const unsigned char *source, int length);
 extern int	pg_utf_mblen(const unsigned char *s);
 extern int	pg_mule_mblen(const unsigned char *s);
 
-/*
- * The remaining functions are backend-only.
- */
-extern int	pg_mb2wchar(const char *from, pg_wchar *to);
-extern int	pg_mb2wchar_with_len(const char *from, pg_wchar *to, int len);
 extern int	pg_encoding_mb2wchar_with_len(int encoding,
 										  const char *from, pg_wchar *to, int len);
-extern int	pg_wchar2mb(const pg_wchar *from, char *to);
-extern int	pg_wchar2mb_with_len(const pg_wchar *from, char *to, int len);
 extern int	pg_encoding_wchar2mb_with_len(int encoding,
 										  const pg_wchar *from, char *to, int len);
 extern int	pg_char_and_wchar_strcmp(const char *s1, const pg_wchar *s2);
 extern int	pg_wchar_strncmp(const pg_wchar *s1, const pg_wchar *s2, size_t n);
 extern int	pg_char_and_wchar_strncmp(const char *s1, const pg_wchar *s2, size_t n);
-extern size_t pg_wchar_strlen(const pg_wchar *wstr);
-extern int	pg_mblen(const char *mbstr);
-extern int	pg_dsplen(const char *mbstr);
-extern int	pg_mbstrlen(const char *mbstr);
-extern int	pg_mbstrlen_with_len(const char *mbstr, int len);
-extern int	pg_mbcliplen(const char *mbstr, int len, int limit);
+extern size_t	pg_wchar_strlen(const pg_wchar *wstr);
 extern int	pg_encoding_mbcliplen(int encoding, const char *mbstr,
 								  int len, int limit);
-extern int	pg_mbcharcliplen(const char *mbstr, int len, int limit);
-extern int	pg_database_encoding_max_length(void);
-extern mbcharacter_incrementer pg_database_encoding_character_incrementer(void);
-
-extern int	PrepareClientEncoding(int encoding);
-extern int	SetClientEncoding(int encoding);
-extern void InitializeClientEncoding(void);
-extern int	pg_get_client_encoding(void);
-extern const char *pg_get_client_encoding_name(void);
-
-extern void SetDatabaseEncoding(int encoding);
-extern int	GetDatabaseEncoding(void);
-extern const char *GetDatabaseEncodingName(void);
-extern void SetMessageEncoding(int encoding);
-extern int	GetMessageEncoding(void);
-
-#ifdef ENABLE_NLS
-extern int	pg_bind_textdomain_codeset(const char *domainname);
-#endif
-
-extern unsigned char *pg_do_encoding_conversion(unsigned char *src, int len,
-												int src_encoding,
-												int dest_encoding);
-
-extern char *pg_client_to_server(const char *s, int len);
+/*
+ * These functions are used from pqformat.h and pqformat.c and therefore need
+ * to be retained here rather than being moved to mbutils.h.  This situation
+ * should be rectified.
+ */
 extern char *pg_server_to_client(const char *s, int len);
-extern char *pg_any_to_server(const char *s, int len, int encoding);
-extern char *pg_server_to_any(const char *s, int len, int encoding);
+extern char *pg_client_to_server(const char *s, int len);
 
 extern unsigned short BIG5toCNS(unsigned short big5, unsigned char *lc);
 extern unsigned short CNStoBIG5(unsigned short cns, unsigned char lc);
 
-extern void UtfToLocal(const unsigned char *utf, int len,
-					   unsigned char *iso,
-					   const pg_mb_radix_tree *map,
-					   const pg_utf_to_local_combined *cmap, int cmapsize,
-					   utf_local_conversion_func conv_func,
-					   int encoding);
-extern void LocalToUtf(const unsigned char *iso, int len,
-					   unsigned char *utf,
-					   const pg_mb_radix_tree *map,
-					   const pg_local_to_utf_combined *cmap, int cmapsize,
-					   utf_local_conversion_func conv_func,
-					   int encoding);
-
-extern bool pg_verifymbstr(const char *mbstr, int len, bool noError);
-extern bool pg_verify_mbstr(int encoding, const char *mbstr, int len,
-							bool noError);
-extern int	pg_verify_mbstr_len(int encoding, const char *mbstr, int len,
-								bool noError);
-
-extern void check_encoding_conversion_args(int src_encoding,
-										   int dest_encoding,
-										   int len,
-										   int expected_src_encoding,
-										   int expected_dest_encoding);
-
-extern void report_invalid_encoding(int encoding, const char *mbstr, int len) pg_attribute_noreturn();
-extern void report_untranslatable_char(int src_encoding, int dest_encoding,
-									   const char *mbstr, int len) pg_attribute_noreturn();
-
-extern void local2local(const unsigned char *l, unsigned char *p, int len,
-						int src_encoding, int dest_encoding, const unsigned char *tab);
-extern void latin2mic(const unsigned char *l, unsigned char *p, int len,
-					  int lc, int encoding);
-extern void mic2latin(const unsigned char *mic, unsigned char *p, int len,
-					  int lc, int encoding);
-extern void latin2mic_with_table(const unsigned char *l, unsigned char *p,
-								 int len, int lc, int encoding,
-								 const unsigned char *tab);
-extern void mic2latin_with_table(const unsigned char *mic, unsigned char *p,
-								 int len, int lc, int encoding,
-								 const unsigned char *tab);
-
-#ifdef WIN32
-extern WCHAR *pgwin32_message_to_UTF16(const char *str, int len, int *utf16len);
-#endif
-
 #endif							/* PG_WCHAR_H */
diff --git a/src/include/common/unicode_norm.h b/src/include/common/unicode_norm.h
index f1b7ef1aa4..e09c1162eb 100644
--- a/src/include/common/unicode_norm.h
+++ b/src/include/common/unicode_norm.h
@@ -14,7 +14,7 @@
 #ifndef UNICODE_NORM_H
 #define UNICODE_NORM_H
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 extern pg_wchar *unicode_normalize_kc(const pg_wchar *input);
 
diff --git a/src/include/libpq/pqformat.h b/src/include/libpq/pqformat.h
index af31e9caba..584e141ac9 100644
--- a/src/include/libpq/pqformat.h
+++ b/src/include/libpq/pqformat.h
@@ -14,7 +14,7 @@
 #define PQFORMAT_H
 
 #include "lib/stringinfo.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "port/pg_bswap.h"
 
 extern void pq_beginmessage(StringInfo buf, char msgtype);
diff --git a/src/include/regex/regcustom.h b/src/include/regex/regcustom.h
index 82c9e2fad8..2506ac8268 100644
--- a/src/include/regex/regcustom.h
+++ b/src/include/regex/regcustom.h
@@ -52,7 +52,7 @@
 #include <wctype.h>
 #endif
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 #include "miscadmin.h"			/* needed by rcancelrequested/rstacktoodeep */
 
diff --git a/src/include/regex/regex.h b/src/include/regex/regex.h
index dc31899aa4..739cc7d14b 100644
--- a/src/include/regex/regex.h
+++ b/src/include/regex/regex.h
@@ -35,7 +35,7 @@
 /*
  * Add your own defines, if needed, here.
  */
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 /*
  * interface types etc.
diff --git a/src/include/tsearch/ts_locale.h b/src/include/tsearch/ts_locale.h
index 17536babfe..f77eb23c8a 100644
--- a/src/include/tsearch/ts_locale.h
+++ b/src/include/tsearch/ts_locale.h
@@ -15,7 +15,7 @@
 #include <ctype.h>
 #include <limits.h>
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "utils/pg_locale.h"
 
 /*
diff --git a/src/include/utils/mbutils.h b/src/include/utils/mbutils.h
new file mode 100644
index 0000000000..737e9d9a59
--- /dev/null
+++ b/src/include/utils/mbutils.h
@@ -0,0 +1,108 @@
+/*-------------------------------------------------------------------------
+ *
+ * mbutils.h
+ *	  backend-only multibyte-character support
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/utils/mbutils.h
+ *
+ *	NOTES
+ *		TODO: write some notes
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef MBUTILS_H
+#define MBUTILS_H
+
+/*
+ * For front-end portability, use pg_encoding_mb2wchar_with_len instead
+*/
+extern int	pg_mb2wchar(const char *from, pg_wchar *to);
+extern int	pg_mb2wchar_with_len(const char *from, pg_wchar *to, int len);
+
+extern int	pg_wchar2mb(const pg_wchar *from, char *to);
+extern int	pg_wchar2mb_with_len(const pg_wchar *from, char *to, int len);
+
+extern int	pg_mblen(const char *mbstr);
+extern int	pg_dsplen(const char *mbstr);
+extern int	pg_mbstrlen(const char *mbstr);
+extern int	pg_mbstrlen_with_len(const char *mbstr, int len);
+extern int	pg_mbcliplen(const char *mbstr, int len, int limit);
+
+extern int	pg_mbcharcliplen(const char *mbstr, int len, int limit);
+extern int	pg_database_encoding_max_length(void);
+extern mbcharacter_incrementer pg_database_encoding_character_incrementer(void);
+
+extern int	PrepareClientEncoding(int encoding);
+extern int	SetClientEncoding(int encoding);
+extern void	InitializeClientEncoding(void);
+extern int	pg_get_client_encoding(void);
+extern const char *pg_get_client_encoding_name(void);
+
+extern void SetDatabaseEncoding(int encoding);
+extern int	GetDatabaseEncoding(void);
+extern const char *GetDatabaseEncodingName(void);
+extern void SetMessageEncoding(int encoding);
+extern int	GetMessageEncoding(void);
+
+#ifdef ENABLE_NLS
+extern int	pg_bind_textdomain_codeset(const char *domainname);
+#endif
+
+extern unsigned char *pg_do_encoding_conversion(unsigned char *src, int len,
+												int src_encoding,
+												int dest_encoding);
+
+extern char *pg_any_to_server(const char *s, int len, int encoding);
+extern char *pg_server_to_any(const char *s, int len, int encoding);
+
+extern void UtfToLocal(const unsigned char *utf, int len,
+					   unsigned char *iso,
+					   const pg_mb_radix_tree *map,
+					   const pg_utf_to_local_combined *cmap, int cmapsize,
+					   utf_local_conversion_func conv_func,
+					   int encoding);
+extern void LocalToUtf(const unsigned char *iso, int len,
+					   unsigned char *utf,
+					   const pg_mb_radix_tree *map,
+					   const pg_local_to_utf_combined *cmap, int cmapsize,
+					   utf_local_conversion_func conv_func,
+					   int encoding);
+
+extern bool pg_verifymbstr(const char *mbstr, int len, bool noError);
+
+extern bool pg_verify_mbstr(int encoding, const char *mbstr, int len,
+							bool noError);
+extern int	pg_verify_mbstr_len(int encoding, const char *mbstr, int len,
+								bool noError);
+
+extern void check_encoding_conversion_args(int src_encoding,
+										   int dest_encoding,
+										   int len,
+										   int expected_src_encoding,
+										   int expected_dest_encoding);
+
+extern void report_invalid_encoding(int encoding, const char *mbstr, int len) pg_attribute_noreturn();
+extern void report_untranslatable_char(int src_encoding, int dest_encoding,
+									   const char *mbstr, int len) pg_attribute_noreturn();
+
+extern void local2local(const unsigned char *l, unsigned char *p, int len,
+						int src_encoding, int dest_encoding, const unsigned char *tab);
+extern void latin2mic(const unsigned char *l, unsigned char *p, int len,
+					  int lc, int encoding);
+extern void mic2latin(const unsigned char *mic, unsigned char *p, int len,
+					  int lc, int encoding);
+extern void latin2mic_with_table(const unsigned char *l, unsigned char *p,
+								 int len, int lc, int encoding,
+								 const unsigned char *tab);
+extern void mic2latin_with_table(const unsigned char *mic, unsigned char *p,
+								 int len, int lc, int encoding,
+								 const unsigned char *tab);
+
+#ifdef WIN32
+extern WCHAR *pgwin32_message_to_UTF16(const char *str, int len, int *utf16len);
+#endif
+
+#endif							/* MBUTILS_H */
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 80b54bc92b..a58619a562 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -28,7 +28,7 @@
 #include "fe-auth.h"
 #include "libpq-fe.h"
 #include "libpq-int.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "pg_config_paths.h"
 #include "port/pg_bswap.h"
 
diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index eea0237c3a..5940ed6705 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -26,7 +26,7 @@
 
 #include "libpq-fe.h"
 #include "libpq-int.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 /* keep this in same order as ExecStatusType in libpq-fe.h */
 char	   *const pgresStatus[] = {
diff --git a/src/interfaces/libpq/fe-misc.c b/src/interfaces/libpq/fe-misc.c
index a9074d2f29..ce3b4ce41e 100644
--- a/src/interfaces/libpq/fe-misc.c
+++ b/src/interfaces/libpq/fe-misc.c
@@ -49,7 +49,7 @@
 
 #include "libpq-fe.h"
 #include "libpq-int.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "pg_config_paths.h"
 #include "port/pg_bswap.h"
 
diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
index 850bf84c96..e8461cd0df 100644
--- a/src/interfaces/libpq/fe-protocol3.c
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -28,7 +28,7 @@
 
 #include "libpq-fe.h"
 #include "libpq-int.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "port/pg_bswap.h"
 
 /*
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index c78891868a..75d6c67560 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -23,7 +23,7 @@
 #include "commands/trigger.h"
 #include "executor/spi.h"
 #include "funcapi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "parser/parse_type.h"
diff --git a/src/pl/plperl/plperl_helpers.h b/src/pl/plperl/plperl_helpers.h
index 1e318b6dc8..cec942c280 100644
--- a/src/pl/plperl/plperl_helpers.h
+++ b/src/pl/plperl/plperl_helpers.h
@@ -1,7 +1,7 @@
 #ifndef PL_PERL_HELPERS_H
 #define PL_PERL_HELPERS_H
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 #include "plperl.h"
 
diff --git a/src/pl/plpgsql/src/pl_scanner.c b/src/pl/plpgsql/src/pl_scanner.c
index 9cea2e42ac..a875c01430 100644
--- a/src/pl/plpgsql/src/pl_scanner.c
+++ b/src/pl/plpgsql/src/pl_scanner.c
@@ -15,8 +15,9 @@
  */
 #include "postgres.h"
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "parser/scanner.h"
+#include "utils/mbutils.h"
 
 #include "plpgsql.h"
 #include "pl_gram.h"			/* must be after parser/scanner.h */
diff --git a/src/pl/plpython/plpy_cursorobject.c b/src/pl/plpython/plpy_cursorobject.c
index 4c37ff898c..01ad7cf3bc 100644
--- a/src/pl/plpython/plpy_cursorobject.c
+++ b/src/pl/plpython/plpy_cursorobject.c
@@ -10,7 +10,7 @@
 
 #include "access/xact.h"
 #include "catalog/pg_type.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "plpy_cursorobject.h"
 #include "plpy_elog.h"
 #include "plpy_main.h"
diff --git a/src/pl/plpython/plpy_plpymodule.c b/src/pl/plpython/plpy_plpymodule.c
index e308c61d50..b079afc000 100644
--- a/src/pl/plpython/plpy_plpymodule.c
+++ b/src/pl/plpython/plpy_plpymodule.c
@@ -7,7 +7,7 @@
 #include "postgres.h"
 
 #include "access/xact.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "plpy_cursorobject.h"
 #include "plpy_elog.h"
 #include "plpy_main.h"
diff --git a/src/pl/plpython/plpy_spi.c b/src/pl/plpython/plpy_spi.c
index 99c1b4f28f..9857114d4c 100644
--- a/src/pl/plpython/plpy_spi.c
+++ b/src/pl/plpython/plpy_spi.c
@@ -12,7 +12,7 @@
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "executor/spi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "parser/parse_type.h"
 #include "plpy_elog.h"
 #include "plpy_main.h"
diff --git a/src/pl/plpython/plpy_typeio.c b/src/pl/plpython/plpy_typeio.c
index e734b0d130..e75f55d622 100644
--- a/src/pl/plpython/plpy_typeio.c
+++ b/src/pl/plpython/plpy_typeio.c
@@ -9,7 +9,7 @@
 #include "access/htup_details.h"
 #include "catalog/pg_type.h"
 #include "funcapi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "plpy_elog.h"
 #include "plpy_main.h"
diff --git a/src/pl/plpython/plpy_util.c b/src/pl/plpython/plpy_util.c
index 4a7d7264d7..873afcfbb8 100644
--- a/src/pl/plpython/plpy_util.c
+++ b/src/pl/plpython/plpy_util.c
@@ -6,7 +6,7 @@
 
 #include "postgres.h"
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "plpy_elog.h"
 #include "plpy_util.h"
 #include "plpython.h"
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index e7640008fd..b163017ee6 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -23,7 +23,7 @@
 #include "executor/spi.h"
 #include "fmgr.h"
 #include "funcapi.h"
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "parser/parse_func.h"
diff --git a/src/port/chklocale.c b/src/port/chklocale.c
index c9c680f0b3..4ebc11bab8 100644
--- a/src/port/chklocale.c
+++ b/src/port/chklocale.c
@@ -23,7 +23,7 @@
 #include <langinfo.h>
 #endif
 
-#include "mb/pg_wchar.h"
+#include "common/pg_wchar.h"
 
 
 /*